All the Mistakes We Once Made
by Kittyaceres
Summary: Dean Winchester, the Mark of Cain, goes back in time, trying in vain to undo his past. (m for the violence)
1. Chapter 1

"Maybe if we―"

"Maybe if you just stopped," Dean interrupted the King of Hell, walking into the warehouse where he and the fallen Angel of the Lord were hidden out, discussing ways to get into Purgatory, for their own, selfish purposes.

It had been a long journey for Dean Winchester to end up here; allowing Cas to work with _Crowley_ to do anything, particularly freeing the Leviathans that had ended up killing Bobby and many, many others, was one of Dean's biggest regrets in life. Aside from the obvious―taking the Mark of Cain, killing Death, accidentally freeing the Darkness, etc., etc. And now Dean had several advantages: he was immortal and he was here, in the past, able to undo his mistakes. And like hell he was gonna undo them.

When Rowena cast the spell to take the Mark off of Dean's arm, it had worked―to an extent. Dean's soul had been split into two, equal and identical copies: one without the Mark, one with. This Dean, here in this warehouse, was the unlucky half who was stuck with it. He couldn't die, not even if he wanted to. He'd tried. He had lived through countless years on the charred remains of an earth completely ravaged by the Darkness. The upside was that because the Darkness had been freed, the Mark of Cain's poisonous effects on him were null and void. He was, essentially, a friendly demon. And he was here now, not knowing of the force that had brought him back.

And now he stared at the unlikely pair, one of whom stared at Dean guiltily like a deer caught in the headlights. The other tried smoothly to talk his way out of this disaster: "Squirrel! What are you doing here? Last time I saw you, you were living a happy life with your girl. What was her name, Linda?"

Dean scowled at him. "Her name's Lisa. As for what happened to me―" Dean blinked, revealing his demon eyes. "The two of you happened to me."

Crowley's eyebrows shot up. "Whoa."

Castiel rushed forward. "Dean, you're a demon? How did this happen?"

Dean backed away from him, returning his eyes to their normal color. "Once upon a time two idiots decided to break into Purgatory and accidentally nearly cause the end of the world."

"That doesn't answer my question, Dean." Dean stared at Cas deadpan.

"I'm not here to answer your questions. Please, just stop what you're doing. I know exactly what you're doing, and why. There is another way. _Find_ _it_. Leave Purgatory alone. _Please_."

In the blink of an eye, Dean was gone, leaving a confused Crowley, and a conflicted Castiel.

"Well, that was something. Where were we?" Crowley asked.

Castiel shook his head. "What? You're just going to ignore him?"

"He's a demon! It's not like we can exactly trust him," Crowley shrugged.

"You're a demon," Castiel pointed out. "Are you saying I can't trust you?"

"We had a deal! I always keep my end of the bargain. He, on the other hand, just came in here demanding everything for nothing! It's a trick."

Castiel, though, wasn't so sure. He sensed Dean longing for him and flew off to check on him. He was both thoroughly confused and relieved to see that Dean was alive, well, and human. He didn't reveal himself, though; he just stood there watching Dean blankly watch tv.


	2. Chapter 2

Several months passed before Crowley and Castiel got a warning from Dean to stop what they were doing again.

They were taking a break from trying to torture the way into Purgatory from the Alphas. It wasn't working.

"This is a bloody waste of time!" Crowley complained.

"I'll say. The monsters only know of one way to get to Purgatory: death. And I'm sure that's gonna be a real help for you two."

"Squirrel. Hello."

"And what the hell are you two doing?"

Neither spoke.

Dean clicked his tongue. "You don't have to tell me. I mean, obviously I already know."

"So, there's two Dean's running around at the same time. How'd that happen?" Crowley asked.

"Well, you know, impending apocalypse...misguidance… I made some mistakes. Now I am eternal."

"Eternal?"

"Yeah. I tried to eat a bullet." Dean waved his hands down his body to emphasize how well that had worked. "I found the Colt and―" Dean mimicked shooting himself in the head. "Hell, I even stabbed myself in the chest with _an angel blade_."

"Why?" Castiel's voice cracked as he asked.

"Everyone I care about died: Bobby, Kevin, Charlie, Claire, Garth, Jody, Sam…" Dean was tearing up. "You," he choked out.

Crowley rolled his eyes. Castiel lurched forwards to comfort Dean but decided against it halfway. His breath was staggered as well.

Dean wet his lips. "Yeah, well… Times were tough. I had more than enough time to get over it."

"Meaning?"

"Meaning, I was alone for thousands of years. _Alone,_ alone. An empty earth I called my home." He looked at Cas: "No heaven." He looked at Crowley, who was looking slightly excited: "And no hell. No Purgatory, even!"

Crowley and Castiel looked at him confused, at each other, and then back at him. Castiel took another half-step forwards. "How did this happen?"

"It's just a downward spiral that starts here, Cas." Dean took a couple steps towards Castiel until they were inches apart from each other. He cupped Castiel's face: "Please, please stop what you're doing. I'm fucking serious, Cas. Don't let that future― _my future_ ―happen. We can find another way to deal with the war in heaven. Please, there's another way. Let's find it. Or just don't do anything at all. I know what you plan to do. Is it right? I've been down the path of slaughter, and it's not fun. It's hard to live with yourself afterwards. You won't want this. I don't want this for you."

Castiel's breath hitched. "Dean…"

"I'm begging you here. Please, Cas."

Dean thought about what he'd gone through, and judging by Castiel's growing despair, he figured that the angel was reading his mind. "Let's go…" he whispered. Castiel nodded.

"Whoa, whoa, wait. All it's gonna take is for Dean here to bat his eyelashes and you do whatever he says? _You're so whipped,_ " he said.

Castiel looked at Crowley, considering what he'd said. Dean pulled Cas's face back towards him. "Cas?"

Cas didn't know what to do or whom to listen to, so he disappeared.

"You've hurt his feelings," Crowley said.

Dean rolled his eyes at Crowley. "You bastard," he muttered. Then, louder, he continued, "You think that Cas is the only one who's gonna get screwed over here, just because he's the only one I'm warning? Bullshit! He's just the only one of you two that I care about. You should realize, though, what you guys are planning, it's not gonna end well. You're gonna get screwed over. We're not the only ones Cas is gonna betray." With that, he disappeared. Crowley shrugged.

* * *

 **The first two chapters were crap and I apologize but it gets better next chapter I promise**


	3. Chapter 3

One would think that with a guy nagging at you for over a year, Dean thought to himself, that you would start to listen to him. One would be wrong.

Dean watched as Castiel stole away into the abandoned warehouse. He sat with his legs crossed on a pile of old pallets with the First Blade sitting on his lap. Nervously, Cas looked around before he pulled out his jar of blood. He didn't notice Dean.

"Just thinking about this makes me sick," Dean said.

Cas set the jar down on the shelf pushed away from the wall. "I thought you may come."

"It took a while to find this place, but I'm here now. I saw you praying, though. To God. I don't think your justification impressed Him much though."

The corners of Castiel's mouth set into a frown. "Who knows what my father thinks?"

"I can think of several preachers I've met who could tell you exactly what He thinks." Dean shook his head, rolling his eyes.

"Since when do you believe in God, Dean?"

"Who do you think brought me here, Cas?" Castiel blinked at him, not responding.

Dean looked down and twisted the First Blade. "So, did you really think that I came here to just talk to you? That I wouldn't be prepared to do _anything_ I could to stop you?"

"I anticipated." Castiel reached within his coat and pulled out a pair of handcuffs. Even from over there, Dean could see the pentagrams etched into the surface.

"Aww, Cas! Are those for me?" Dean batted his eyelashes.

"Yes. Is that for me?"

He looked down at his blade. The old bone looked so innocent for a blade so powerful. "Doesn't have to be. Last chance: don't do this, Cas."

But Castiel was determined. And when he was determined… Well, not even the prospect of death could stop him.

Dean, in a move faster than the angel's eyes could track, leaped off of the pallets. He lunged for the jar of blood, ready to smash it to the ground, so Castiel couldn't use the blood. Cas, though, moved just so he slammed into him, causing them to both crash to the ground. Dean was sprawled over him, and he moved the blade to Castiel's neck, warning the angel not to make a move.

"You know, I never quite imagined it this way," he said. Castiel blinked. Dean stabbed him in the shoulder and, kneeing him in the privates, he leapt to his feet and swiftly grabbed the jar of monster blood.

Castiel pulled the blade from his shoulder and let it clatter to the floor. He leaped up and spun Dean around and pressed him against the shelves. Before Dean could "accidentally" drop the jar, Cas pulled it from his hand and placed it on the top shelf.

"Cas, please," Dean begged weakly. It had no effect on Castiel. He slammed Dean's head into the shelf behind him, making his vision go red. He grabbed Dean's hands and cuffed him up.

"It's a means to an end, Dean."

"It's not." Dean felt weaker. Was this how all demons felt inside of devil's traps or these fucking handcuffs? Or was that just the pain of Castiel's betrayal hitting him again? It couldn't just be the head trauma he'd just suffered. "It's not," he repeated. Castiel was bleeding down his front. Dean looked at it, ducking his head. Castiel had bled when the Leviathans used him as their vessel. Blood had come out of his ears, his eyes, his nose…if Dean remembered it right. All that remained of him was his trenchcoat once they were done with him. Where had Cas turned up when he was resurrected from the river?

Dean looked into the the angel's eyes. "This is the beginning of a new era. One of blood, and pain, and disorder. There's no end, Cas. Only Darkness."

"I don't see it. And I'm not listening to a demon." Cas dragged him away and slammed him face down into the cement with all his might. And as an angel, Castiel had a lot of might.

Yep, there were definitely cracks in his skull. Dean fought to keep conscious as he rolled over onto his back. His vision was dim and blurry, but he was sure that that was a devil's trap on the ceiling.

Cas was chanting. Panic gripped Dean: "Cas!" he croaked as loudly as he could manage. He was fading fast. He imagined he heard Cas stop chanting. He forced himself to whisper, "Goodbye. I―I lo-ve... _you_."

Everything went black.

* * *

 **What? Me? Writing a cliffhanger? Well, I never!**


	4. Chapter 4

**To all you Destiel shippers out there: HAHA WHAT LOVE CONFESSION?! THAT NEVER HAPPENED WHAT ARE YOU TALKING ABOUT**

* * *

Dean woke up with two fingers pressed to his forehead and Castiel looking down at him with a look of concern. It didn't feel real though. It didn't feel legitimate. Dean sat up and looked beyond Castiel. _Oh no…_

"You did it?" Dean scrambled away from Castiel. The devil's trap only let him go so far.

"Yes."

"You idiot."

"It's what I had to do, Dean."

"Just leave me here to rot."

"No." Dean looked at him confused. "You _are_ Dean Winchester. You Winchesters are crafty. If I were to leave you here alone or with a guard, you'd charm or kill your way out. And then you'd try to stop me from under my nose. No. You're coming with me; you're never leaving my side. That's the only way I can be sure that you don't sabotage me."

"You're not gonna last long enough for me to sabotage you," Dean scoffed.

"I am stronger than you think."

"How many times do I gotta explain this to you? _I have been here before._ I know exactly what's gonna happen, and it ain't pretty."

Castiel ignored him. "Come, it's time to leave."

"I am _not_ leaving with you!" Castiel pressed his fingers to Dean's forehead, knocking him unconscious.

Dean woke up to Cas. "I am your new God. Bow down and profess your love unto me. Or I will destroy you all."

There was a ringing in his ears. That didn't usually happen when Cas zapped him somewhere. Other than the bowel movement complications, it was generally a smooth ride. Dean stood, feeling horribly tipsy. Those damn Leviathans…"You're no god," he mumbled. Bobby, Sam, and Dean (his past self) stared at him in awe, probably wondering who he was and how he was there. Castiel turned around. Dean shuffled around for balance.

"You are no god," he repeated. "You are just a pathetic angel who's trying to contain a plethora of primordial goo with a god complex. They're slipping through, I can see it. The arrogance, the bloodlust, that feeling of more-more-more. You're losing the fight. It's too late. This is the beginning of the end."

Castiel gave Dean a patronizing smile, which made his blood boil with anger. He struggled against the the chains. Castiel waved his hand, and Dean found his lips sealed together.

The other Dean took a step towards the poisoned angel. "Cas… is this true?" Castiel turned back towards him. Behind his back, Dean nodded.

"No, Dean. I am in control." Dean rolled his eyes dramatically and shook his head.

"Who's that?" Sam asked.

"This is my prisoner. He tried to stop me." Castiel said. "I cannot kill him, so I must take him with me."

Dean rolled his eyes again. He pointed at Cas, shook his finger, pointed to his ears, and pointed to himself. He pointed at the angel again and twirled his finger by his ear. What he was attempting to say was, "He didn't listen to me; he's an idiot."

Sam gasped for breath.

"Not doing so well, are you, Sam?" Castiel asked. Dean growled.

"You said you'd fix him!" the other Dean shouted.

"I said, if you stand down. Which you didn't. You tried to kill me. But still, enjoy my mercy. I could have cast you into the pit. I could kill you all for your infidelity. But I have no reason to kill you. You were once my favorite pets, before you turned around and bit me. The sentiment remains, and I would find it quite hard to kill you." Castiel's calm, complacent tone irritated Dean. He kicked him in the back of the knee.

Castiel turned around so quickly that Dean didn't realize that he'd been knocked out...until he woke up.

He woke up in a cluttered living room. It took a few moments to realize: this was Bobby's house! He was tied to a chair inside of a devil's trap. The handcuffs had been left on.

Dean's past self sat in a chair, supposedly watching him, except he'd fallen asleep, resting on his hand.

"Castiel is going to come for me," he warned. "I imagine the only reason he didn't take me with him was because you can't sneak a demon into heaven, no matter how hard you try."

Dean 1.0 woke up suddenly. "What?"

"I was warning you that Castiel is coming for me once he finishes killing his brethren in Heaven."

"Is that what he's doing?" Dean 2.0 nodded.

Dean 1.0 grimaced. "Let's stop talking about him. Let's talk about you. Who are you?"

"Name's Winchester. Dean Winchester."

The other one rolled his eyes. "Okay, Bond. How'd you get here?"

"God sent me, to undo what's happened in my time."

Past Dean nodded. "You've come from the future to prevent it from happening? You're doing a great job, I must say."

Dean snorted. "Oh, 'Godstiel' and the Leviathans? Don't worry about it. The 'Godstiel' crap's only gonna last a couple days. He'll realize I was right and come crawling back to you to undo it all. Much worse things are going to happen in the next few years."

"Like what?"

"First, a Knight of Hell. Then, all the angels get locked out of heaven. Next, we work with _Crowley_ and get the Mark of Cain. Then Crowley's mom got involved, and...well like mother like son. She helped get the Mark off of me, which released the Darkness. Then everyone died. The end." Dean tapped his hands on the arms of the chair. "Any questions?"

Dean 1.0 asked, "What happens to Cas?" Dean 2.0 smirked. His past self rushed forward and gripped his shirt. "WHAT HAPPENS TO CAS?!" he shouted.

"You know, I see now why people think we're lovers." His past self tightened his grip, his fingernails digging into his chest. "Okay! He dissolved in the river. You really think _one_ angel can handle _all_ of Purgatory?"

Bobby entered. "What are you doing, Dean?"

"Interrogation," Dean 2.0 answered with a curt nod. The other Dean let go of him and told Bobby what he knew.

The room shook. Dean squirmed in his chair. "I warned you. He's gonna take me. This is gonna hurt…" He braced himself. The shaking changed to a jarring, nauseating, moving-up-and-down-several-feet quake. Dean landed face down in a sandbox. He propped himself on his elbows and puked out all the bile in his stomach.

"Hello, Dean."

"Castiel," he croaked.

Castiel didn't speak. Dean struggled to stand. He swayed on his feet and looked around. This playground was familiar. The post-teleportation sickness clouded his thoughts, so he couldn't be sure. He _thought_ that this was the same playground that, in a couple years, would serve as the permanent door to heaven.

 _Not if I have anything to do about it._

Castiel cocked his head. "Let's go, Dean. Our work is about to begin."

" _Your_ work. I got nothing to do with this." Castiel sent him another patronizing smile.


	5. Chapter 5

Castiel started with preachers. Any preacher he deemed hypocritical he smote. Then law enforcers. White supremacists. Sexist business leaders. Motivational speakers. His list of immoral people grew and grew.

Tagging along when Castiel flew wasn't getting any better. Dean began eating as much food as he could just so he'd have something other than bile in his stomach to throw up. Castiel was getting worse. He had moments, Dean could see, where the evil inside of him was forcing its way to the outside. Castiel would stop and grimace; his breathing would grow ragged and he'd need to lean on something. Usually thereafter, he'd go cure someone of a physical ailment to prove to himself that he was good. Dean saw right through him.

Three days later, Castiel visited Crowley's hideout―a trailer graffitied with angel warding. Dean collapsed on the floor. He stumbled to his feet in search of something to vomit in. He heard Crowley swear and decided that, because Crowley is a douchebag, he'd vomit right on the floor.

Crowley glared at him. "Oi!"

Dean leaned on an end table and glared back at him.

Crowley diverted his attention back to Castiel. "I suppose you've come here to kill me. Want a drink first?" Castiel shook his head. "Ah you like to bend them right over, do you? Let's go." Crowley braced himself to be smote.

"I'm not going to kill you, Crowley. I have plans for you."

"Whussit?" Crowley looked angry, and somewhat scared.

"Here's our new arrangement: you return to your post as King of Hell. But, I control where each soul goes. I control the flow; you take what you get." Castiel waited for Crowley's reaction. Crowley looked horrified.

"Hell's getting downsized," Crowley summed up.

"That's a terrible deal! Don't take it," Dean suggested.

Ignoring Dean, Castiel said, "I would do away with it all together, but I need something to hold over my enemies. And we must keep Michael and Lucifer in the cage."

"This isn't a negotiation, is it?" Crowley asked.

"No."

"I'm sold then!" Crowley turned around to pour them drinks, but Castiel whisked away without another word. Dean was growing sick of this.

Another day passed, and, all of a sudden, Castiel's skin was covered in blisters. He and Dean sat at a park bench, talking.

"They're trying to get out," Dean noticed.

"I'm handling it."

"You're melting, Cas. You're the Wicked Witch undergoing Chinese Water Torture." Dean waved his hands and rolled his eyes, knowing Castiel wouldn't listen to him.

"I don't understand that reference."

"You can't control it, Cas. Take it from the guy who's tried to control a pre-biblical force before. It's impossible." Dean reached out to touch his face. His skin broke under Dean's fingertips, and they came away bloody. "Look at this Cas! You gotta face the music, man! Quit playing God!"

Castiel's jaw set. "I can handle it."

"Then heal yourself," Dean challenged him. Castiel brought his hand to his face, but once the light had faded, his skin was just as angry and red as before. The bleeding, though, had stopped.

"Congratulations, you're as useful as a bandaid." Castiel glared at him. "You've got two days left―three tops. Make 'em count."

"Are you asking that I return the souls to Purgatory?"

"That's exactly what I want."

Castiel smiled and shook his head. That damn patronizing smile again… "There's a problem with your plan, Dean."

"I'll find a way. I've been to Purgatory many times."

Castiel was about to ask how, but he was distracted by a prayer in his head. "They've bound Death."

"Ah, that wasn't one of my better ideas…"

"They plan to kill me."

"Yep."

Castiel didn't warn him before dragging him away. Dean hit the carpet at such a velocity that his nose, forehead, and chin got rug burn. He cursed. He rested on his cheek and watched as Castiel and Death went back and forth, Death explaining about the Leviathans and calling Castiel stupid for becoming their vessel (something Dean had said so many times in the past few days he'd sounded like a broken record), and Castiel threatened to kill him. Instead of killing him, though, Castiel freed Death and dragged Dean away, yet again, to "bring justice" to another immoral individual.

Dean barfed onto the linoleum floor. He groaned and wondered where Cas had brought him this time. He sat back, looking around. There was a lot of red, white, and blue. His vision cleared enough to see that they were in a senator's office. He focused on Cas, who was telling an intern how he was a better god than his father. A strange smile grew on his face. For the first time, Dean felt downright afraid of Cas.

It was laughable. Here he was―an invulnerable slave to the Darkness, cowering in fear from _an angel_. Not even an archangel. That smile though, it was worse than his patronizing one. He felt the air pressure drop slightly, not enough to make him pass out, but enough to make his ears pop. He watched in horror as Castiel, with that beast-like grin on his face, ripped out the throat of everyone in the room. Castiel looked at him, and Dean shrank into the glass door, trying to make himself as small as possible.

The smile went away, and Castiel passed out onto the floor, his blood mixing with the others'. Dean should have gone over and checked that Castiel was okay. He couldn't move though. Terror gripped Dean. He stared around the room at all the dead bodies who'd been brutally massacred moments earlier.

Slowly Cas came to. He stood and surveyed what he'd done, a look of horror growing on his face. Dean heard the chains trembling, and he realized it was him. What if _they_ took control again? They couldn't kill him, he knew, but they could do a lot of damage.

Cas looked like the he was falling under their control again, his lips twitching up into a grin. Dean needed to ground him. It had worked in the past―technically the future―when Cas was under a different mind control. He took the risk: "Cas? Buddy?"

Cas looked over at him, panicked. "I did this?"

"Yeah. They're slipping through, Cas." Castiel looked around. He looked like he wanted to cry. Dean stood up cautiously and said, "Let's go Cas. Away from here."

Castiel nodded and flashed them out, to a forest clearing with a large lake in one direction. It looked to be completely untouched by man. Or at least, it did when Dean regained his strength. Stars still dotted the night sky but to the east there were touches of orange on the horizon. "Where are we?"

"We are in a nature preserve in Idaho. This place is unknown to most humans and completely isolated."

Dean shifted so he wasn't sitting on the chains. "Wanted to be alone, huh?"

"I like it here. I find it calming. I, uh, marred my happy place, so here we are."

"If you stay here long enough, you'll mar this one too."

"I don't plan on staying." Castiel sat cross legged on the ground next to Dean.

Dean tried to figure out what that meant. Was he just facing the truth, or was he downright suicidal? Castiel reached into his coat and pulled out an angel blade and the First Blade. He handed them to Dean.

"Wow, giving your prisoner weapons. I don't know if that's such a good idea, Cas."

"I know what you're thinking, and if it comes to it that's what I want you to do." Cas looked up and stared him in the eyes. His blue eyes were bloodshot, but still they silently persuaded Dean to give into Castiel's will. "Please help me get rid of them."

Dean looked away from his eyes and held out his chained hands. "Yes of course," Castiel said, and he used his powers to unlock the chains.

Dean's wrists were sore. He rubbed at them. "Thank you." He inspected them. "Not as good as the Men of Letters' but they do the job." He tucked them into his pocket and concealed the weapons inside his coat as well.

He stood. "So! You want to return all those souls you're harboring back to Purgatory!" Dean clapped his hands together. What you're going to need is some more Purgatory native blood. I can go―"

"I've got that."

Dean looked at him, confused. "You do? Oh no, no, no, I remember now. Then you're set! The Winchesters will help you." Dean teleported away.

"Dammit Dean!" cursed started with preachers. Any preacher he deemed hypocritical he smote. Then law enforcers. White supremacists. Sexist business leaders. Motivational speakers. His list of immoral people grew and grew.

Tagging along when Castiel flew wasn't getting any better. Dean began eating as much food as he could just so he'd have something other than bile in his stomach to throw up. Castiel was getting worse. He had moments, Dean could see, where the evil inside of him was forcing its way to the outside. Castiel would stop and grimace; his breathing would grow ragged and he'd need to lean on something. Usually thereafter, he'd go cure someone of a physical ailment to prove to himself that he was good. Dean saw right through him.

Three days later, Castiel visited Crowley's hideout―a trailer graffitied with angel warding. Dean collapsed on the floor. He stumbled to his feet in search of something to vomit in. He heard Crowley swear and decided that, because Crowley is a douchebag, he'd vomit right on the floor.

Crowley glared at him. "Oi!"

Dean leaned on an end table and glared back at him.

Crowley diverted his attention back to Castiel. "I suppose you've come here to kill me. Want a drink first?" Castiel shook his head. "Ah you like to bend them right over, do you? Let's go." Crowley braced himself to be smote.

"I'm not going to kill you, Crowley. I have plans for you."

"Whussit?" Crowley looked angry, and somewhat scared.

"Here's our new arrangement: you return to your post as King of Hell. But, I control where each soul goes. I control the flow; you take what you get." Castiel waited for Crowley's reaction. Crowley looked horrified.

"Hell's getting downsized," Crowley summed up.

"That's a terrible deal! Don't take it," Dean suggested.

Ignoring Dean, Castiel said, "I would do away with it all together, but I need something to hold over my enemies. And we must keep Michael and Lucifer in the cage."

"This isn't a negotiation, is it?" Crowley asked.

"No."

"I'm sold then!" Crowley turned around to pour them drinks, but Castiel whisked away without another word. Dean was growing sick of this.

Another day passed, and, all of a sudden, Castiel's skin was covered in blisters. He and Dean sat at a park bench, talking.

"They're trying to get out," Dean noticed.

"I'm handling it."

"You're melting, Cas. You're the Wicked Witch undergoing Chinese Water Torture." Dean waved his hands and rolled his eyes, knowing Castiel wouldn't listen to him.

"I don't understand that reference."

"You can't control it, Cas. Take it from the guy who's tried to control a pre-biblical force before. It's impossible." Dean reached out to touch his face. His skin broke under Dean's fingertips, and they came away bloody. "Look at this Cas! You gotta face the music, man! Quit playing God!"

Castiel's jaw set. "I can handle it."

"Then heal yourself," Dean challenged him. Castiel brought his hand to his face, but once the light had faded, his skin was just as angry and red as before. The bleeding, though, had stopped.

"Congratulations, you're as useful as a bandaid." Castiel glared at him. "You've got two days left―three tops. Make 'em count."

"Are you asking that I return the souls to Purgatory?"

"That's exactly what I want."

Castiel smiled and shook his head. That damn patronizing smile again… "There's a problem with your plan, Dean."

"I'll find a way. I've been to Purgatory many times."

Castiel was about to ask how, but he was distracted by a prayer in his head. "They've bound Death."

"Ah, that wasn't one of my better ideas…"

"They plan to kill me."

"Yep."

Castiel didn't warn him before dragging him away. Dean hit the carpet at such a velocity that his nose, forehead, and chin got rug burn. He cursed. He rested on his cheek and watched as Castiel and Death went back and forth, Death explaining about the Leviathans and calling Castiel stupid for becoming their vessel (something Dean had said so many times in the past few days he'd sounded like a broken record), and Castiel threatened to kill him. Instead of killing him, though, Castiel freed Death and dragged Dean away, yet again, to "bring justice" to another immoral individual.

Dean barfed onto the linoleum floor. He groaned and wondered where Cas had brought him this time. He sat back, looking around. There was a lot of red, white, and blue. His vision cleared enough to see that they were in a senator's office. He focused on Cas, who was telling an intern how he was a better god than his father. A strange smile grew on his face. For the first time, Dean felt downright afraid of Cas.

It was laughable. Here he was―an invulnerable slave to the Darkness, cowering in fear from _an angel_. Not even an archangel. That smile though, it was worse than his patronizing one. He felt the air pressure drop slightly, not enough to make him pass out, but enough to make his ears pop. He watched in horror as Castiel, with that beast-like grin on his face, ripped out the throat of everyone in the room. Castiel looked at him, and Dean shrank into the glass door, trying to make himself as small as possible.

The smile went away, and Castiel passed out onto the floor, his blood mixing with the others'. Dean should have gone over and checked that Castiel was okay. He couldn't move though. Terror gripped Dean. He stared around the room at all the dead bodies who'd been brutally massacred moments earlier.

Slowly Cas came to. He stood and surveyed what he'd done, a look of horror growing on his face. Dean heard the chains trembling, and he realized it was him. What if _they_ took control again? They couldn't kill him, he knew, but they could do a lot of damage.

Cas looked like the he was falling under their control again, his lips twitching up into a grin. Dean needed to ground him. It had worked in the past―technically the future―when Cas was under a different mind control. He took the risk: "Cas? Buddy?"

Cas looked over at him, panicked. "I did this?"

"Yeah. They're slipping through, Cas." Castiel looked around. He looked like he wanted to cry. Dean stood up cautiously and said, "Let's go Cas. Away from here."

Castiel nodded and flashed them out, to a forest clearing with a large lake in one direction. It looked to be completely untouched by man. Or at least, it did when Dean regained his strength. Stars still dotted the night sky but to the east there were touches of orange on the horizon. "Where are we?"

"We are in a nature preserve in Idaho. This place is unknown to most humans and completely isolated."

Dean shifted so he wasn't sitting on the chains. "Wanted to be alone, huh?"

"I like it here. I find it calming. I, uh, marred my happy place, so here we are."

"If you stay here long enough, you'll mar this one too."

"I don't plan on staying." Castiel sat cross legged on the ground next to Dean.

Dean tried to figure out what that meant. Was he just facing the truth, or was he downright suicidal? Castiel reached into his coat and pulled out an angel blade and the First Blade. He handed them to Dean.

"Wow, giving your prisoner weapons. I don't know if that's such a good idea, Cas."

"I know what you're thinking, and if it comes to it that's what I want you to do." Cas looked up and stared him in the eyes. His blue eyes were bloodshot, but still they silently persuaded Dean to give into Castiel's will. "Please help me get rid of them."

Dean looked away from his eyes and held out his chained hands. "Yes of course," Castiel said, and he used his powers to unlock the chains.

Dean's wrists were sore. He rubbed at them. "Thank you." He inspected them. "Not as good as the Men of Letters' but they do the job." He tucked them into his pocket and concealed the weapons inside his coat as well.

He stood. "So! You want to return all those souls you're harboring back to Purgatory!" Dean clapped his hands together. What you're going to need is some more Purgatory native blood. I can go―"

"I've got that."

Dean looked at him, confused. "You do? Oh no, no, no, I remember now. Then you're set! The Winchesters will help you." Dean teleported away.

"Dammit Dean!" cursed Castiel.

* * *

 **Wow this chapter was exactly 3,000 words! _In other news_ , how many of you are extremely angry at me right now? I know that if I was a reader, I wouldn't be sitting here laughing. **

**Please review. I like reviews.**


	6. Chapter 6

Did Dean feel bad for ditching Castiel? Yes. Did he doubt that Castiel would go running to his past self for help? No. Did that numb his guilt? A little.

These were the thoughts that went through his head that night as he tried to sleep. As a demon, Dean didn't need to sleep, no. But, he figured, after a week of being dragged around and in pain, he should sleep.

So, Dean thought about what he'd done as he tried to sleep in his bed at the Men of Letters' bunker.

 _Wow, you dick, you abandoned him in the forest when you needed you. Doesn't that sound familiar? Oh yeah, because that's exactly what he did to you, back in Purgatory! Remember how much that one stung? And then he abandoned you again! Remember how much_ that _hurt?_

Dean groaned. He couldn't go after him, though; there were things that Cas had to go through, as much as Dean hated to put him through them.

Dean covered his face in the pillow as guilt washed over him. He was turning into the exact thing he didn't want to be: a manipulative, mysterious, black-eyed bastard. Well, he wasn't a bastard...but he was a jerk.

" _Bitch_ ," he whispered.

Dean drifted off to sleep a couple hours later.

God visited him in his dream. Dean had first met him, as _God_ , back when Amara had tried to go back in time. She hadn't quite achieved what she'd wanted, bringing them back to the alternate universe that Zachariah had zapped Dean back to in 2009. There had been turmoil, _three_ Deans, and Lucifer's death, and Amara repeating what she'd done. She didn't like the archangels very much. And then towards the end, Chuck Shurley had approached Dean and given him the chance to undo it all. Apparently he was God all along.

Currently, they were on the side of the river where Castiel had dissolved. Well, currently that would be _is dissolving_. They looked on as Castiel waded in from the opposite side of the river, and Sam, Dean, and Bobby watched in horror.

"Castiel is reckless," Chuck sighed.

"Can they see us?" Dean asked.

"No. This is a dream, Dean."

"In real time."

"Yes."

Dean stared at the darkening waters. "I was supposed to stop this," he whispered sadly.

"Somewhere out there you did," Chuck assured him.

"What, in some other universe?" Dean asked.

Chuck nodded. "Dean, you mustn't worry about this failure. There is still time to do what you've come to do. And then if you fail again, we'll find a way to make it better." Dean sighed.

Across the water, Dean picked up Castiel's trench coat sadly. He, Sam, and Bobby started walking away.

Chuck made his way down to the shoreline. He fished around in the water until he pulled out a tanned hand. Connected to the hand was a tattered, white dress shirt; connected to that was a shoulder; connected to that was an exhausted-looking Castiel. Chuck heaved him onto the shore, where Castiel lay, unmoving.

"Someone will find him, take him to a hospital. He'll be diagnosed with amnesia. No one will be the wiser about this entire situation," Chuck told him.

Dean stared at the passed-out angel.

"And, Dean, I told you to keep your mission hush-hush. I've wiped the memories of your past self and everyone whom he told about you of all information about you. Keep this _secret_ this time."

"Yessir."

With that, Dean woke up.

* * *

 **Do any of you share the headcanon that Chuck is God? It's a pretty universally accepted headcanon among the fandom.**


	7. Chapter 7

**A/N: I was originally going to have Dean seek out Cas and pour his heart out to him because I am Destiel trash but then I thought, _Eh... that's too gay. Better just have Dean and Crowley argue with each other._**

* * *

Dean sat up in bed. Castiel was alive, out there somewhere. Was he in the hospital? Was he still lying on the shore bed of the river? Dean left the bed and dressed. He moved to the foyer of the bunker and sat down at the large war table.

The Leviathans escaping Purgatory had caused red lights to appear all along the Missouri River. Dean had never realized just how quickly the Leviathans had spread themselves out, and he was alarmed to see lights spreading into the states of Kansas, Missouri, and Nebraska. Some were even as far as Wyoming, _already._ It blew Dean's mind.

Dean left the Bunker to search for Cas. Of course, it was a stupid idea, but…he had to make sure that his best friend was okay.

When he got to the river bank, though, Cas was gone. Dean looked around, searching nearby hospital emergency rooms, but to no avail. Dean struggled to remember (it had been so long ago for him) what Cas's fate had been. He'd…met a woman, in Colorado…or somewhere around there… There'd been a demon; Dean definitely remembered that. Was Cas's wife the demon…or had a demon attacked her while Cas was out? Dean figured it'd been the latter. Cas would have known if he was married to a demon.

Although demons did seem to be his type, Dean thought bitterly, as an afterthought.

He decided to let the trail run cold, taking God's advice to back off (as much as he hated to).

About a month or two later, Dean was sitting in a park, absolutely bored out of his mind. Nothing special about that.

But then, of course, Crowley showed up.

"You're from the future, you said?" Crowley asked without preamble.

"What—no hello?"

"Just answer the question, squirrel."

"I thought I made it pretty obvious."

"Right. You defeated the Leviathans, then?"

"Of course I did." Dean sat up from his lounging position on the park bench.

"Good," Crowley said. "Tell me how you did it."

Dean cocked his head and smirked. "Why? Did the Leviathans not want to play with you?"

Crowley scowled at him. "I just think it's in my best interests not to side with them is all."

"Because you asked and Dick Roman said no."

Crowley held three fingers up, ready to snap them. "With only a click of my fingers, I could have every demon and hellhound in hell attack and hurt you, boy. Don't test me; tell me how you defeated the Leviathans."

Dean grinned. "Your empty threats don't scare me Crowley. And besides, most of them hate you, don't they? I'm certain that if I asked, they'd willingly turn on their king."

Crowley and Dean glared at each other, waiting for the other to back down.

Crowley caved first. "FINE! Don't tell me! Let them destroy the world for all I care!"

"No, Crowley, you're right, I'll tell you." Dean stood up. "But first you'll need a couple of… _ingredients_."

"What are they?"

"First ingredient: the blood of a fallen angel."

Crowley winced. _Ha yeah, good luck with that little man._ "What else?"

"The blood of the leader of the fallen. Demons, that is. Your blood."

Crowley rubbed his chin. "I could get my hands on that…"

"Ready for the last ingredients?"

Crowley nodded.

"Too bad. If the Leviathan touch you and gain your knowledge, then it's game over. So, it's imperative that we don't give them too much information. Do you understand?"

"I suppose that's how they know the path the two of you traveled on your hunts?" Crowley asked.

"What?" Dean stared at Crowley. "How do you know that?"

"What? I read the books. They're following your journey, as you and Sam: Jericho, California; Lost Water Creek, Colorado; Catasauga, Pennsylvania… I suspect they'll be going to Toledo next."

"Shit."

"Maybe you should tell me the rest of those ingredients, and we can whip up a Leviathan killing potion, huh?" Crowley wheedled.

"It's not a potion, Crowley."

Crowley ignored him. They stood there for a long moment.

Crowley broke the silence: "So, d'you reckon you could kill a Leviathan with the First Blade?"

Dean thought for a moment. "Maybe. You wanna find out?"

"Why don't we go kill your photocopies?"

"I will be doing all the work-just so we're clear, Crowley."

Crowley cocked his head and gave one of his charming smiles. "I wouldn't have it any other way."

* * *

 **A/N: Yes you would, Crowley. You'd have Dean give you all the ingredients upfront if you could have it your way, BUT THIS ISN'T BURGER KING, CROWLEY! WE DON'T GET TO HAVE IT OUR WAY ALRIGHT!?**

 **So starting next chapter we're gonna ignore canon alright? Not that I haven't been doing that already, but you know how it goes writing fanfiction...**


	8. Chapter 8

The first one they caught by surprise-stabbed him in the back of the head. Dean and Crowley had teleported themselves into the car that the Leviathans disguised as Sam and Dean had been driving. The Leviathan Dean was driving, and this is the one that Dean stabbed. He slumped onto the steering wheel, causing the car to veer off the road, landing upside down in a ditch. Black goo dripped from the back of its head, until the goo pooled on the roof of the car.

Crowley nodded and hummed his approval.

The remaining Leviathan spun around and stared at Dean. It shifted its gaze to Crowley, then back to Dean. In those few moments, it looked scared; and why wouldn't it? It had just witnessed its brethren killed—a feat which should be impossible. Its fear didn't last long, though, and it grinned maliciously. "Ah, Castiel's little pets. Come to avenge your master, I see?"

"Fuck you," Dean growled.

The Leviathan laughed—Sam's laugh. That just made Dean angrier. "I'm going to kill you," Dean whispered. "And you know I can."

"So does every one of us. And now we're all going to be hunting you down. That is, if I don't kill you first."

"Hey, I've been trying, but if you find a way, I'd love to hear it," Dean drawled.

The Leviathan and Dean both climbed out of the car. Crowley climbed out too and pulled his cell phone out, to film the two of them.

The Leviathan cracked its knuckles and punched Dean in the face. The force of it sent Dean stumbling back; he heard bone crack. The Leviathan punched Dean over and over. "I like my meat well _tenderized,_ " it explained.

"Well, in that case—" Dean's fist connected with its face. It hardly seemed to have felt it. Dean slammed his foot into the Leviathan's solar plexus. He was pleased to hear it gasp for breath and to see it stumble back and fall flat on its back. Dean pulled a bottle of borax from where it was concealed within his jacket. He grabbed a fistful of its hair and splashed the borax in its face.

"You know why this burns, don't you? It's because you're so filthy; you're a dirty, unholy oil stain," Dean said in a low tone. "That's why God locked you away, you filthy son of a bitch."

"It's a curious thing that you haven't been locked away by that logic."

"I am a storm door, holding back a much, _much_ worse storm." Dean conveniently left out the fact that he was no longer _holding back_ that storm.

Dean let go of the Leviathan, standing and kicking its face and gut. He scooped up the First Blade from where he'd dropped it. He'd yet to turn back to the Leviathan before he felt a knife stick into his neck. The Leviathan plunged the knife into Dean's windpipe. Dean whirled around and stabbed it in the back. It died almost instantly. Dean pulled the knife from his throat and fell to the ground, legs unable to hold his weight up.

Crowley ventured over, pointing the camera at the leaking Leviathan, then at Dean.

"What—" Dean rasped.

Crowley understood what he'd been trying to ask: "Helping."

Dean died before he got the chance to ask exactly how Crowley was helping.

Crowley stopped filming. He brought up the Washington Post homepage, and tapped their contact information page. He sent them an email with the video of "Sam and Dean Winchester's" deaths.

He slipped his phone back into his pocket and inspected the corpse that laid at his feet. "So much for being eternal," Crowley lamented. He picked up the First Blade, wiped the goo off with a hanky, and disappeared with a click of his fingers.

* * *

 **AHHHH OH NO GUYS DEAN'S DEAD WHO AM I GONNA WRITE ABOUT NEXT?!**

 **Hahaha just kidding he's not actually dead, he just hasn't respawned yet, that's all!**


	9. Chapter 9

**Canon? What canon?**

* * *

Rufus's Cabin A Short Time After Crowley Emailed The Washington Post

Bobby was taking a break from torturing Chet. It wasn't getting him anywhere anyway. He sat at the couch and scanned the news for any news on the Leviathans dressed as Sam and Dean. Jody sat next to him with a laptop on her lap, looking online.

"Hey, check this out," she said. She pushed the laptop to face Bobby. She clicked a Youtube video titled "MURDER BROTHERS SAM AND DEAN WINCHESTER BRAWL TO THE DEATH."

It showed exactly that: what _looked_ like Sam and Dean fighting each other, calling the other unsavory things, and then Sam stabbing Dean in the back; Dean turnring quickly and stabbing Sam in the back; Sam falling face first on the ground; Dean pulling the knife from his throat before stumbling backwards onto his butt himself. Then, the video showed the person filming moving closer; Dean, not quite dead yet asking what he was doing.

A chill went down Bobby's spine when the camera man answered, sounding a hell of a lot like Crowley, that he was helping. Then the facsimile's eyes unfocused, and he died.

"That sounded a hell of a lot like Crowley…" Bobby mused

"Who's Crowley?"

"Demon. King of Hell."

"Why would the king of Hell be helping the Leviathans?" Jody asked. Bobby shook his head and shrugged his shoulders. He watched the video again.

"I think only one of those is a Leviathan," he said. "Look, see the black goo bleeding out of Sam's body? Now look at Dean, his blood is red…"

Bobby pulled his cell phone and called Dean.

"Hey, Bobby! Did you find a way to kill these nasty SOB's?" Dean asked on the other line.

Bobby breathed a sigh of relief. "You're alive!"

"Why wouldn't I be? We haven't even reached Iowa yet."

"Someone posted a video of the Leviathans dressing up like you killing each other—"

"Killing each other? How?" Dean interrupted.

"They stabbed each other. It's just while Sam's bleeding black, you're blood's pooling red, boy. I was scared."

Dean hummed thoughtfully. "We haven't encountered them. That's really weird. Do you know who posted the video?"

"It says anonymous, but my guess is Crowley. I heard his voice."

"And, the rest of the article says that when the police arrived at the scene of the crime, investigators found a pool of goop where the one posing as Sam was lying, but Dean was still…uh, intact. The Impala they were driving was flipped over, with more black goo pooled on the roof of the vehicle," Jody said, looking at the laptop.

Bobby relayed the information to Dean. Dean thought for a moment. "How long's it take for a Leviathan to reform?" he asked.

"Not long. Certainly not as long as it would have taken for the authorities to get to the crime scene."

"Should we come back?" Dean asked.

"Yeah, I think that'd be the best for now."

* * *

Later in a Hospital near the Crime Scene

Dean woke up on a cold metal table, a scalpel cutting into his bare chest. He was naked, with a thin hospital blanket covering him from the hips down. He opened his eyes—black—and took a deep breath. The coroner screamed. Her scalpel tore at Dean's flesh painfully as she jumped back.

"Hello to you too," Dean muttered.

The coroner ran towards him and plunged her scalpel into Dean's chest before running out of the room calling for help.

Dean pulled the scalpel out and rubbed at his chest. It'd heal. He left back to the bunker, to get some new clothes. His old clothes were probably in an evidence locker somewhere…and possibly the First Blade. Fuck.

Dean decided to go to Crowley first. He wanted to know how Crowley had been "helping" him.

Crowley jumped at the sight of Dean. "What did you expect? That I'd stay dead?" Dean asked. "When do I ever do that? And besides, I told you I'm eternal. Can't die, not even if I want to? Were you not listening?"

Crowley shrugged. "Eh, you were talking and all I heard was 'ANGST!' and 'Cas, run off with me because I love you!' and 'Crowley's evil; don't work with him' and 'Why don't you love me?' It was all very boring. I mostly just tuned it out. I suppose you'll be wanting your blade back?"

"You have it?"

Crowley quickly backtracked. "Eh, no I just thought—"

"Of course you have it," Dean interrupted. He held his hand out. "Give it to me Crowley."

"Why should I? Let's go after Dick, and then you can have it back. To kill Dick."

Dean lifted an eyebrow. Crowley was…scared. Scared that Dean would kill him when he got his hands on the blade. Ha! "Or, you could give it to me, and then I'll go after Dick Roman alone."

"What, you don't want to go after him together? Just you and me—two most powerful demons, taking down the most powerful monster. Whaddya say?"

Dean tapped his chin. "Or, I could just go get it myself." He looked at Crowley thoughtfully. "Wouldn't be too hard to find."

"I don't know where it is. I told one of my henchmen to go hide it careful and then kill himself so if the Leviathans come looking for it, and they find him they can't find out where it was hidden." Crowley smirked at him.

"Wow," Dean said. "That was…actually sort of clever. Congratulations." Crowley beamed. "Now go find it."

Crowley scowled. "How the hell am I supposed to do that? It could be on the moon, for all I know!"

"Then look on the moon," Dean shrugged.

Crowley upped the ante on his scowl.

"Or of course, I could find it myself…and then kill you. Been meaning to check that off my to-do list…" Dean picked at his nails, pretending to be disinterested in whichever way this turned out.

Crowley huffed. "Fine!" With a click of his fingers, he disappeared.

Dean smirked. He knew he would always be able to play on Crowley's fatal flaw of self-preservation. That is, he _would_ be able to, if he didn't kill Crowley anyway when Crowley returned with the first blade.

* * *

 _ **#Crowley ships it**_

 **Please review! If you liked it, that is. If you didn't like it, then...￣\\_(ツ)_/￣**


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